As peroxisome proliferator-activated receptor alpha (PPAR-α) is the primary regulator of FA oxidation in the heart [28], and has paradoxically been shown to have a blunted response to FAs in obesity [29], one hypothesis is that increased PPAR-α activity in response to improved insulin resistance and reduced fat mass, is responsible for the decrease in MTGC seen here. Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.